In general, bags may be largely classified into a handbag carried by a hand and a shoulder bag slung over a shoulder or shoulders.
Shoulder bags have been disclosed in Korean Utility Model No. 0392083 and the like. Those bags can be slung over shoulders by the shoulder straps.
In detail, shoulder straps make a ring shape in the entire form and both ends are coupled to the bag. A user puts on the bag by putting the arms through the rings made by shoulder straps such that the shoulder straps go over the shoulders.
This type, however, has a problem in that when the user wearing the bag runs, the shoulder straps come off and the bag slips down. Further, bags are considered as articles for carrying loads, so they are difficult to use for fashion.